Oil-burning locomotive furnace



March 2, 1928. 1,664,099

H. A. ATWATER OIL BURNING LOCOMOTIVE FURNACE Original Filed Oct. 8, 1923 2 Sheets-Sheet 1 iv w27/ess: N

March 27, 192s. 1,664,099

H. A. ATWATER OIL BURNING LOCOMOTIVE FURNACE Original Filed 001;, 8, 1925 2 Sheets-Sheet 2 1 Lil Patented Mar. 27, 1928.Y

UNITED STATES rari-iur orricii. r

HARRY A. ATWAT'ER, or KANSAS CITY, MISSOURI.

OIL-BURNING Locoiuoiivn romance.

Application filed October B, 1923, ySerial No.l 667,177. Renewed November 30, 1927.

The present invention relates to improvements in the construction of locomotive lireboxes, and particularly to that type of construction which is adapted for oil burning, and the primary object in View is to prowhich 'much ofthe heat loss by radiatioii from the bottom surface of the pan VWillbeY prevented.

` A further object of the invention is., to promote the eflici'e'ncy of the combustion within the reb'oinby means of an air supply in Awhich airis eectiv'ely preheated on its way lto Ythe burner. j

VFor this purpose I have devised a ireboX construction in which the fire pan is' formed with a llame/channelV extending fromgthe burner through the lower portion of the firebo'X, and also with an air-preheating passage underlying all sides of saidl'tl'ame vchannel and adapted to subjectl the air, prior to its admission to the burner, to an effective prehea'ting action by being` conducted from one end of the firebox to the Vother over the hot exterior surfaces of said iiamiechannel.

lIncidentally it is sought to prolong life of fireboX structures of this type, by virtueof a more even, uniform temperature being maintained, y sharpy temperature changes in that part of the structure which is most directly exposed to the outside air currents. i

l/Vi'th the foregoing general objects in view, the invention will nowYV be 'described by reference to the accompanying drawings illustrating a practical forinof embodimentof the saine, after which those features deemed to be novel will be particularly set forth and claimed. f

In the drawing- Figure l is a central vertical sectional view illustrating Va locomotive fireb'ox einbodying the present improvements;

Figures 2 and 3 are transverse sections taken on the lines II-II and III-HI rethe and the elimination of flue sheet but also to increase the length of flame travel within the reboX, 'as required for efficient combustion of the fuel. This archh 'as proved very dilicultan'd expensive to maintain under the severe 'conditions im'- posed by locomotive practice, and Yexperience has shown that the use of the arch does not effect the same increase in oil fuel economy as vattends its use injcoal-burning fireboxes, and consequently the tendency for several years hasb'een tok favorthe location of the burner at the front end of the firebox- Vrest isadmitted through the sides v'of the tire pan, or by means -of a boot' through the bottoni of th'e pan. Unless some special means is provided for preheating allor a part of this air, its ltemperature at the point of admission 'will approach that of the `sur-` roundingatmosphere, and the-result is ret'ardinjg ofthe oil ignition and a idecrease in the possible length'of flame travel, and a resultantftendency t-o the formation'of carbon in' the irebox, aswell Jasian aggravated ments` of the steam and oil lconnections to the burner are not very carefully regulated. These 'conditions bring about sharp temperature variations and a localization 'of high and low temperature areas, and lead Vto such iirebox troubles as broken stay-bolts, cracks' oi' fractures and leaks in 'the furnace and boiler structure, and materially decreased 'life in the firebriclz lining of the Firebox. The object of the present improvement 'is to eliminate such troubles to a very great exten-t, by promoting vva more uniform temperature within and around the lirebox and a more e'flicient combustion of the liquid f-uel.v

ln the drawing, the fiiepan construction is illustrated as comprising vtheusual lrear or iiash wall plate 3, Aand side shelf sheets 4 suitably secured t`o the mud ring 5er lower ends of the inner 'sheets 6 of the side water legs. To Ithe inner margins of vthe side shelf sheets 4 aie secured side sheets extending downwardly and having their lower edges conc nected by a bottonrpla'te 8,.thereby Yforming a longitudinally extending depressed portion VS5. popping of the oil flame in case the adjustfor providing a flame channel 9 through the middle portion of the draft pan and below the level of the side shelf portions 4. At the front end of the fire pan is located an end shelfor table sheet 10 overlying and extending forward of the burner 11 and its connections 12 to the front water leg 13.

Spaced laterally from the side sheets 7 a suitable distance and 'parallel thereto are additional exterior side sheets 14 depending 'from the( sheets 4 and havingV their lower margins connected by a bottom sheet 15, and

Y thus enclosing an air-preheating passage 16 surrounding the exterior side an-d bottom facesof the flame channel portion of the pan. The rear lend of this passage 16 is open, as indicated at 17, for'theintalie of air,"while the front end of the `passage is l.closed by Va plate 18 mounted in position between the front ends of the sheets 14 and plate 15 andthe under face of the sheet 10 (see Figures 1 and 2). This plate is rcmovably secured by bolts 20, or the` like, to permit access to the burner 11 and connections 12, said burner being positioned in a Y compartment 21 at the front of the flame channel and separated by adjustable partition plates 22 from the front end of the passage 16,'by the adjustment of which plates, bymeans of bolts 23 engaging slots 24 (see Figure 4), the flow of air through said compartment may Vbe conveniently regulated.

' Y The floor and sides of the lire pan and flame channel 9 are lined with firebriclr 25 in the usual manner, and4 through the side 1 walls of said flame channel ,arey preferably through the passage 16 all heat whichn'iay be given off at moments of excess pressure in the iirebox, and also. serves to protect adjacent parts fromV contact with any flame issuing from. the passages 26.

A boot member 30 may also be provided for comlucting additional outside air through the bottom sheet 15 to an opening 31 in the bottom of the flame passage 9. The interior ofv this boot is entirely closedfroln comn'iunication. with the air passage 16, and

the rear side of the boot is provided with a hinged door adapted to be opened to different degrees to regulate the intake' flow of air vthrough Vthe boot. No communication is provided between the boot opening 31 and the air-preheating passage 16 because the main flow of air, when the locomotive is working, enters byY Way of the burner compartment 21, through which a strong draft pull is always acting, whereas the boot and side air passages26 may admit air only intermittently due to the effect of back pressure at these points caused by sudden expansion of the gases of combustion and particularly noticeable when'thelocomotive is being worked hard at low speed.

Infthe usual fire pan construction, the bottonrplate is exposed to swiftly moving air currents when the locomotive is in motion, thereby necessarily resultingA in the radiation of a very considerable amount of heat. In addition to this actual wastefof heat, the flrebriek lining is subjected to a.v

cooling action. Now since the rapid ignition of the oil issuing from theeburner is de-Y pendent to a very great extentwupon the heat reflection from the hot firebrick lining, act# ing as an inverted refractory arch, theV cool-r ing of this lining, combined with the further cooling effect caused byv the inrusli of cold air through the burnerv compartment, very seriously interferes with the rapid and steady ignition of the oil, with consequent sharp variations in temperature within the firebox and the operating troubles always accompanying such conditions.

With the'present improvement, a protective sheathing of air space fis provided around the sides and bottom of the flame channel portion of the fire pan, through which a flow of air is maintained for pre heating purposes throughout thelength of said flame channel and finally discharged into the burner compartment. With this arrangement, all the heat absorbed by the air in its course through the prelieating passage 16 is'carried back into the firebox, while the radiation from the outside walls of the passage 16 is practically negligible since the surfaces of these walls are obviously not at the relatively high temperature of the inside walls 7 and bottom plate-8, which are kept highly heated by their direct contact with the firebrick lining of the flame channel. It is apparent, therefore, that a very considerable amount of radiation is prevented Which would otherwise take place.

Another beneficial result ofthe improved construction is the speeding up of the ignition at the burner. It will be understood that before ignition of the oil can take place, the atomized oil and surrounding volume of air not only must be heated to the ignition temperature, but sufficient additional heat must be absorbed to take care of the` latent heat of vapor-ization of the oil. hen the velocity of the incoming mixture of oil and air is considered, it is of course apparent that the time available for this heat absorption is necessarily very brief, and hence the utilizationV of preheated air to speed up the les ignition of the oil and produce a longer effective flame length becomes an important feature.

One common fault with the operation of fire-box constructions of previously known types has been the particularly unsteady action of the lire at times when the locomotive is drifting or standing'by, the fire frequently going out and then re-igniting with consequent sharp changes in the firebox teinperatuie, causing undesirable flashing and drumming pulsations. Vith the improved construction and preheating arrangement, a more complete and uniform flame propagation is obtained, insuring a steadier fire at all times, for not only is the cooling of the fiiebrick lining by heat radiation through the fire pan plates greatly reduced, but-the direct cooling action on the inside sui'faces caused by the flow of cold air into the firebox is also practically eliminated. This enables a higher temperature to be maintained in the firebox lining, with steadier'and a more uniform ignition of oil. Y

As a further important benefit following the maintenance of higher temperatures in the incoming air and in the lirebrick lining, the improved construction eliminates to a inark'eddegree the formation and deposit of carbon in the lirebox, which fact is practical proof of efficient burner action and completeness of fuel combustion.

IVhile I have shown and described one common type of firebox construction in connection with the improved air-preheating feature, it is to be understood that the invention is not limited to use with the precise firebox construction herein illustrated; for example, the invention is equally adapted for either the front or rear end burner arrangement, and either with or without a main arch in the firebox or an ignition arch over the burner, and it is likewise immaterial whether the ordinary firebox construction is employed or one with the Graines wall type. I therefore desire to limit the invention only as defined in the appended claims.

IVhat I claim is: l

1. In an oil-burning` locomotive `fir-ebox construction, a lire pan conilpirising side shelf portions and a longitudinally extending depressed portion providing a flame channel between and below the level of said shelf portions, exterior side and bottom walls spaced from the sides and bottoni of said depressed portion and cooperating therewith to form an air-preheating passage, and a burner compartment forming a communieating passage between said flame channel and one end of said preheating passage, the bottom or floor of said depressed portion being closed as regards communication with said preheating passage.

2. In an oil-burning locomotive firebox construction, a lire pan comprising side shelf portions and a longitudinally exten-ding depressedportion providing a iame channel between and below the level of said shelf portions, and exterior side and bottom walls spaced from the sides and bottom of said depressed portion and cooperating therewith to form an air-preheating passage, and a burner compartment forming a communieating passage between said flame channel 'I and one end of said preheating passage, the' bottom or floor yof said depressed portion being closed as regards communication with said prel'ieating passage, andthe side vwalls of said depressed portion having air passages for feeding air through said walls into said flame channel.

3, In an oil-burning locomotive firebox construction, a fire pan comprising side shelf portions arid a longitudinally extending ydevbetween and below the level of said shelf portions, a burner compartment at one end of said flame channel, and exterior side and bottom walls spaced from the sides and bottom of said depressed portion and cooperating therewith to form an air-preheating ypassage communicating with lsaid lburner compartment and having its air intake endv adjacent to the opposite end of said flame channel. 1

5. In an oil-burning ylocomotive firebox construction, a tire pan comprising side shelf portions and a longitudinally exten-ding depressed portion providing a flame channel between and below the level of said shelf portions, a burner compartment at one end of said flame channel, exterior side and bottom walls spaced from'the sides and bottoni of said depressed portion and cooperating therewith to form an air-preheating passage communicating with said burner compartment and having its airintalre end adjacent to the opposite end of said fiame channel, and means for regulating the flow of air from said passage through said burner compartment.

In witness whereof I hereunto affix my signature.

HARRY A. ATVATER.

llO 

